The purpose of this non-clinical, IIDEA project is to identify, clone, and characterize the murine gene corresponding to the human p47-phox gene which codes for the phagocyte protein deficient in autosomal recessive Chronic Granulomatous Disease. No human subjects are involved. An antibody to human recombinant p47-phox detects a protein of nearly identical size in murine bone marrow. DNA analysis of a series of mammalian, avian,and yeast DNA's revealed DNA fragments homologous to the human gene. Primates were most similar and murine DNA less so. Studies of RNA isolated from two murine cell lines 1C21 and WEHI-3 detected mRNA transcripts for the murine p47-phox gene of about 2.5-3.0 kilobases in size. To clone this gene, a cDNA library made from mRNA isolated from WEHI-3 cells was screened using a radioactively labelled human p47-phox cDNA probe. Positive clones were purified and characterized. Five clones were identified as being 2.6-2.8 kb in size. These clones were subjected to DNA sequence analysis. Comparison of the murine and human DNA sequence has revealed 80-85% identity between the murine gene and the human gene in the region of the gene coding for protein. In the majority of cases, base differences occur in the third or "wobble" position of the triplet codon and do not result in amino acid changes in the protein. In the coming year, utilizing gene targeting techniques, the murine gene will be mutated in situ by homologous recombination in an embryonal stem (ES) cell line creating a pluripotent cell line deficient in the murine cytosolic protein. These ES cells can be introduced into murine blastocysts to generate mice carrying an abnormal gene. These animals will provide a model system for studying the inflammatory response and for genetically correcting their defect. This will provide information on potential ways to correct the human genetic defect in the future.